Explanation:

- Option 3: Hardly he had

- This segment contains a grammatical error. The structure should be "Hardly had he" instead of "Hardly he had." The inversion is required after "hardly" to form a correct sentence.

- Option 1: fell on the roof

- This part of the sentence is grammatically correct. It describes the action of the tree falling accurately.

- Option 2: out of

- This is correct and indicates the movement away from the house.

- Option 4: when a tree

- Grammatically correct, introducing the clause about the tree falling.